IBM Deskstar 75GXP Ultra ATA 100 Hard Driveby Scott Gooden on July 26, 2000 12:00 PM EST
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The IBM Deskstar 75GXP series incorporates several new technologies that help to enhance drive performance. By utilizing glass media (data platter’s), a differential preamplifier, and fifth-generation GMR (Giant Magnetoresistive Heads) heads, IBM was able to increase track capacities an average of 41 percent. Due to the increased data densities and fast spindle rates of the 75 GXP, IBM has incorporated a thermal monitor into the drives, to help ensure data reliability.
The 75 GXP is also the first desktop drive that includes IBM’s safety ramp feature. The safety ramp feature safely parks the data heads off the media surface when powering down which helps to protect data during spin up/ spin down cycles. In order to help keep drive noise down, a laminated top cover and ceramic spindle bearings are used, together they can reduce drive acoustics by up to 7 dB.
By utilizing the above technologies, the IBM Deskstar 75GXP series of drives are able to achieve data densities of 15.3 GB’s per platter. The high densities allow the top end drive in the 75 GXP model line to top out at 75 GB’s of storage capacity, by utilizing 5 platters, hence the 75 GXP model name. Along with the 15.3 GB/platter data densities, the 75 GXP drives have spindle speeds of 7200-RPM, allowing the drive to obtain sustained transfer rates of 37 MB/s, according to IBM.
In addition to the 15.3 GB per platter densities, and 7200-RPM spindle speed, the 75 GXP has an average seek time of 8.5 ms and a 2 MB of cache memory. Combining the 8.5 ms average seek time with the 4.17 ms latency, typical of a 7200 RPM drive, the 75 GXP has an overall access time of 12.7 ms. The 2 MB of on-board cache allows data being read from the disk to be more adequately buffered during sequential transfers, as well as allowing more data to be stored from read ahead operations, thus taking better advantage of the 75 GXP’s high speed interface.
The IBM 75 GXP is also one of the first drives on the market to use the new Ultra ATA/100 interface. This interface allows data transfers between the disk drive and IDE controller on the motherboard, of up to 100 MB/s. While the actual sustained throughput of any single drive falls far short of this specification, the benefits of having such high bandwidth shows up when transferring bursts from the hard drives cache memory. It is also helpful when using multiple disks on the same IDE channel, such as when using a striped RAID array.
In order to operate the IBM 75 GXP disk drive under the Ultra ATA/100 interface; you must have an Ultra ATA/100 controller card installed, or utilize a motherboard which has an Ultra ATA/100 compatible chipset and BIOS. In addition, you will need to use a 40-pin, 80-conductor IDE cable, in order to connect your drive to the motherboard or controller card. These are the same cables as currently used for the Ultra ATA/66 drives, so you can use one of these if your drive did not come with one. If your system does not meet the above requirements, the drive will not run at Ultra ATA/100 speeds. However, it is full backward compatible, so if you fall into the above situation, your drive will fall back to either Ultra ATA/66, or Ultra ATA/33 speeds, depending upon your system configuration.
One additional thing we will mention quickly is; if you are new to using disk drives which use either the Ultra ATA/66 or UltraATA/100 interfaces, the 40-pin, 80-conductor cables that these drives require have color coded connectors. You would connect the cable as follows: the blue connector is attached to the motherboard or controller card, the black connector is for the drive you have set as Master, and the gray connector is for the drive you have set as Slave.